Keyboard perforator transmitter



R. A. LAKE KEYBOARD PERFORATOR TRANSMITTER Original Filed Oct. 4, 1937July 16, 1940.

ww Ev mm mm INVENTOR R O S S A. L A K E v Patented July 16, 1940KEYBOARD PERFORATOR TRANSMITTER Ross A. Lake, Oak Park, 111., assignorto Teletype Corporation, Chicago, 111., a corporation of DelawareOriginal application October 4, 1937, Serial No. 167,139. Divided andthis application July 1, 1939, Serial No. 282,359

8 Claims. (Cl. 178-80) This invention pertains to printing telegraphapparatus and particularly to a keyboard actuated mechanism for thepreparation of a signal controlstrip.

This application is a division of application Serial No. 167,139 filedOctober 4, 1937, which eventuated into U. S. Patent No. 2,190,291, datedFeb. 13, 1940.

.The primary object of the invention is to provide an efficient andeasily operable keyboard apparatus for the production of signal controlstrips.

Another object is to render the key action of such keyboard apparatussmoother and lighter to the touch. I

A further object is to provide a means eliec tive under certainconditions for removing from the key lever action the pressure impartedby certain of its functional elements.

The present invention contemplates for the attainment of the above andother objects of the invention, a keyboard mechanism arranged with aplurality of keys operatively associated with pairs of verticallymovable permutation bars through which interponent bars of a perforatingmechanism are moved selectively to control the operation of punch pinsallotted thereto and to perforate a tape correspondingly.

According to the preferred embodiment of the present invention, thecontacts for controlling the character counter have been moreefiectively located from the standpoint of enhancing the key action.Since the function of the counter control contacts is to route anelectrical circuit through 35 either a registering magnet or a releasemagnet in the counter of the type; for example, in accordance with U. S.Patent No. 2,018,368, it is necessary to condition the counter controlcontact springs before the punch operating contact is closed. Due to theinherent structure of prior designs of such apparatus, it was necessaryto close the punch operating contact near the extreme end of the keystroke, making the touch, or key movement, undesirably deep. In thespecific embodiment shown, both the depth of the stroke and the keypressure required to operate the perforator-transmitter have beenreduced.

vertical contact-operating arms, through the instrumentality of whichthe operation of the counter control contacts is accomplished early inthe stroke of the keys. The small camming levers are so arranged thatthey will be pushed completely to one side by the key lever during thefirst half of the key stroke. During the last half of the key stroke,there is no further displacement of the camming levers. The camminglevers are articluated to horizontal bars so that the vertical motion ofthe key lever is transferred to a horizontal motion by means of whichthe counter control contact levers are enabled to actuate the countercontrol contacts. This construction precludes any unnecessary movementof the counter control contact springs when the key is depressed to itsmaximum displacement. counter control contacts are also completelyoperative before the code selection is set up so that there is amplemargin-between the routing operation of the counter control contacts andthe operation of the punch magnet contact.

Another feature of the invention resides in the provision of means forholding the universal hail depressed or out of engagement with the keylevers while the keyboard device is being operated to perforate a tapeonly. The specific form according to the present invention involves aflat spring used to disengage the trip pawl. The spring possesses theadvantage of permitting the trip pawl to be freed from the intermediatebell crank lever, which it normally engages, before the universal baildraws the trip pawl forward.

The spring, therefore, performs the desired dis-- engagement of the trippawl from said bell crank lever relatively early and provides a yieldduring the latter part of the travel of the tape-keyboard switch lever,By means of this feature, the load or effort of operating the universalbail has been removed from the key levers when the perforatortransmitter is being used as a perforator only.

A better understanding of the invention may be had from the followingdescription, taken in conjunction with the accompanying drawing,

wherein: V

Fig. 1 is a longitudinal sectional view of the keyboard mechanismaccording to the present invention;

Fig. 2 is a plan view of the counter control contact assembly;

Fig 3 is a simplified wiring diagram of an electrical control circuitthat may be employed in connection with the present invention; and

Fig. 4 is a fragmentary perspective view to illustrate the control ofthe clutch mechanism by the tape-keyboard switch lever.

Referring now to the drawing in which like reference characters are usedto designate similar parts throughout the several figures, there isshown in Fig. 1 a keyboard ll supported by a base casting l2. Positionedto the rear of the base casting l2 and suitably journaled thereto is apivot rod l3. To the pivot rod I3 a plurality of key levers 14 arerotatably mounted which are normally biased to horizontal position byindividual springs (not shown), and which are provided, as is the usualpractice, at their forward ends with keytops l5 arranged in banks.

Beneath the key levers Hi, and extending transversely thereof, are aplurality of pairs of code bars I6. Each pair of code bars Iii comprisesa bar H and a bar It, and these bars are all provided at each end withvertical slots or notches I9 and 2] respectively, which fit over guidecombs 22 and 23. The bars Ill and iii are thus held against longitudinalmovement, but are free to be shifted vertically in response to theoperation of key levers Hi.

Pivotally mounted on rods 24 and 25 are pairs of rocker arms 26 and 21interposed between code bars I! and H3. The rockerarms 26 and 21 aresubstantially T-shaped, with their free ends formed with oppositelyoff-set lugs. lugs are disposed on opposite sides of the pivot rods 25and 25 and are spaced some distance therefrom. One of the lugs of eachrocker arm projects forwardly into'a notch on the lower edge of thecorresponding code bar ll, and its companion lug projects rearwardlybeneath the companion code bar l8. With this arrangement, the depressionof either code bar of the pair of bars l6 rocks the arms 26 and 2? andlifts the companion, code bar. To the depending portion of the T-shapedrocker arms 26 and'2'l is articulated a longitudinally movablepermutation bar 28. Thus, when the code bars I! and I8 are movedvertically in accordance with the depression of a key lever M, thepermutation bar 28 individual to a pair of bars H and I8 is movedlongitudinally.

Each of the key levers It is arranged, when operated, to engage anddepress one of the permutation bars of each pair'of code bars l6 and toset these code bars in accordance with a character code combination. Toachieve this object, the upper edges of'the code bars ll and I8 arenotched to provide high and low portions in accordance with therespective codes. Also, the bars of each pair of code bars arecomplementary; that is, the notches of one bar are opposite theprojections of its companion bar. The interconnection between the barsof each pair of bars [6 by means of the rocker arms 26 and 2'! {preventsthe simultaneous depression of two key levers. If an attempt is made tooperate more than one key lever at a time, the key levers can only bedepressed for a short distance, when they will be blocked by the highportions of the code bars. By such construction, the simultaneousdepression of two key levers and the transmission of an incorrect signalis prevented.

The key lever and permutation bar construction and arrangement are thesame as disclosed in Patent No. 1,884,753 of October 25, 1932, issued toH. L. Krum, and for further details thereof reference should be made tothe cited patent.

The perforator comprises a set of code punches 29 movable through anopening in upper and lower guide plates 3! and 32 and cooperative with adie plate 33 to perforate a tape 33. The plates 3| and 33 are spacedapart to form a tape guide.

Said

Intermediate the guide plates 3| and 32 is a stripper plate 35 whichcooperates with shoulders on the punches, and due to the action ofsprings 36 operates to remove the punches clear of the tape followingthe operation of a punch hammer 31. The code punches 29 are selectivelyoperated by the actuation of the punch hammer 3? on a set of punchinterponent bars 38 corresponding in number to the punches 29.Operatively associated with each of the bars 38 is a pivoted arm 39which is connected to the permutation bar 28 by means of a link 4|. Theinterponent bar 48 for the feed-hole punch pin is immovable and is fixedat its right-hand end (Fig. 1) to an arm 40 secured to the perforatorframe 50.

The hammer 31' rocks about its pivot 62 and 'forms the armature of anelectromagnet 43.

The hammer 31 comprises a comb portion 44 for guiding the interponentmembers 38 and 48. In accordance with the disclosure in copendingapplication Serial No. 151,364, filed July 1, 1937 by C. W. Burcky, thehammer surface of portion M comprises two intersecting planes 45 and 1'6and a raised rib ll on one of said planes. The code punch interponentbars 38 are adapted to slide on the plane surfaces 45 and 46, while thefeed-hole punch interponent bar 48 cooperates with the raised rib 31.Thus at all times the upper surface of the feed punch interponent bar#18 is higher than the corresponding upper surfaces of interponent bars38. The function of the two intersecting planes and the raised rib is tocompensate for the rocking motion of the punch hammer 3'5 to maintainsubstantially the same relation between interponents 38 and 48 in boththe clockwise and counterclockwise positions of the hammer 31. When apunch hammer such as hammer 31, having two planes and a raised rib forthe feed hole punch interference bar 48 is used, it is desirable toadjust the lateral position of the interference bar 48 (rightward orleftward position, as viewed in Fig. 1) under the feed hole punch.Accordingly, the arm 40 on which bar 48 is mounted is made adjustable byproviding for the insertion of shims 49.

Pivotally carried at one end of punch hammer 3? is a pawl member 55which cooperates with ratchet teeth 56 of a spacing roller 57 which isprovided with feed pins 58 adapted to mesh with the feed holes which areinvariably perforated in the tape 34. Thus, when the magnet 43 isenergized and the hammer 3'l is rocked to its clockwise position, pawl55 is raised to engage a tooth 56 on the spacing roller 51. Then, upondeenergization of magnet 43, spring 53 actuates the hammer 3? to itscounterclockwise position and draws pawl 55 downwardly, which movementcauses the spacing roller 57 to be rotated counterclockwise one angularstep to effect the spacing of the tape 34 one unit distance.

In addition to the live pairs of code bars l6 there is provided, asdisclosed in Patent No. 1,965,602, a universal bar (not shown),associated with a rocker assembly the bar 28 of which is connected by alink ll to a contact operating lever (not shown) associated with a pairof contacts 52 (Figs. 1 and 3) for controlling the operation of thepunch magnet &3. Upon operation of any key lever l6, contacts 52 areclosed and an energizing circuit for perforating magnet '43 iscompleted, causing magnet 43 to operate, whereupon hammer 3'! will berocked to its clockwise the tape 34 in accordance withcode-combinations. Upon the deenergization of magnet 43 the punches 29are withdrawn and the tape 34 is advanced one step under the influenceof spring To indicate to the operator the number of code signalsperforated in the tape so that he may be be apprised when apredetermined number of character code combinations have been perforatedin the tape, or a number sufiicient to fill a line of printing, acounter, the electrical control elements of which are indicated in Fig.3 by reference numeral H), is positioned to the right of the mainmachine, and may be of the construction shown in U. S. Patent No.2,018,368. Consequently, by observing the position of a pointer withrespect to the scale of the counter ID, as fully disclosed in saidpatent, the operator can constantly note the number of character codecombinations perforated in the tape from the beginning to the end of theline, and can determine the position at which the carriage and/orcounter return key should be depressed for correspondingly perforatingthe tape to control a receiving printer. In order to operate the counterHi to indicate the condition referred to, an electromagnet 5| isprovided (Fig. 3), which functions for each key operation (unless itscircuit is opened as noted hereinafter) to cause the advancement of anindicating pointer (not shown) a predetermined amount. The circuit forelectromagnet 5|, as indicated in Fig. 3, extends through the contactsprings BI and $2 of contact bank 5|], and the contact springs 52. Inother words, the contact springs 6| and 62 are normally closed and areso related to the contacts 52 that when the latter contacts are closedfor causing energization of the punch electromagnet 43, a circuit islikewise completed through the electromagnet 5|. Upon the completion ofthe circuit for the electromagnet 5|, it is actuated and causes theassociated pointer to move over the scale for indicating the number ofcharacter code combinations perforated in the tape as disclosed inPatent No. 2,018,368. When a predetermined number of character codecombinations have been perforated in the tape, or a number sufiicient tofill a line of printing, a mechanism on the counter H is operated tocause the closure of contact 54. The closure of this contact completesthe circuit for a lamp 59, which signals the operator of the approach ofthe end of the line.

The operator in noting this signal operates the carriage return key andin so doing, an energizing circuit is completed for an electromagnet 18,in a manner which will presently appear, to control the restoration ofthe pointer of the counter ill to its normal or zero position.

P It is desired in connection with certain of the function key levers,such for example as shift and unshift, line feed and carriage return, toprevent the operation of the counting mechanism or counter I0. Upon thedepression of these particular key levers, actuation of counter I0 is65, 61, 58 are provided at their upper ends with cam portions whichcooperate with the function key levers of the series of key levers I4.Each of the camming levers is provided with a vertical projection H toprevent the accidental disengagement of said levers from cooperativerelation with their associated key levers l4. Camming levers 65, 66, and61- are, in the present embodiment, disposed to the rear of bracket 69and their lower ends are pivotally articulated to a horizontal bar 72.At the left-hand end of bar 12 is fixed a vertically directed contactoperating member 13.

Gaming lever 68 is mounted on the forward face of bracket 59 and ispivotally articulated to a horizontal bar M. Bar 14 is also pivotallyconnected by means of a link 15 to bracket 69 so that bar It is movablewith respect to bracket 59 in a parallel motion manner. There is alsofixed to the left-hand end of bar 14 a contact operating member 16,corresponding to member 73.

Contact operating members 13 and 16 cooperate with contact springs 6|,62, and 63 of contact bank 55 (Figs. 1 and 2) which is carried on abracket 17 mounted on base casting I2. When those key levers M allottedto the shift, unshift, and line feed functions are operated, they arecaused, through the cam portions of their associated camming levers 65,65, or 61, to actuate said camming levers clockwise (as viewed in Fig.l) to move bar 12 l-eftwardly to actuate contact operating member 13correspondingly, which movement causes contact spring 62 to be separatedfrom contact spring 6|, thus breaking the circuit to the counteroperating magnet 5|. It is understood that the punch operating contacts52 are invariably operated upon the depression of a key lever M throughthe instrumentality of a universal bar previously alluded to, but thecircuit for the punch operating magnets is independent of the circuitfor the counter or stepping magnet ,5I, said circuits being in parallel.

The depression of the'carriage return key lever will actuate camminglever 68, through the cam portion thereon, in a counterclockwisedirection, which movement imparts rightward motion to bar it to actuatecontact operating member 16 in a corresponding direction. This movementof member it causes the disengagement of springs 52 and 5| and theengagement of contact springs 6| and 63 to complete an energizingcircuit for an electromagnet 18 in the counter |0 which controls therestoration of the pointer of the counter iii to its normal or zeroposition in the manner disclosed in Patent No. 2,018,368. The energizingcircuits for the electromagnets 5| and 18 may be traced over theconductors clearly disclosed in Fig. 3. It will be noted that thecamming levers are so arranged that they will be pushed completely toone side by their associated key levers during the first half of thestroke of said key levers. During the last half of the key stroke, thereis no further displacement of the camming levers.

When the perforator mechanism, according to the present invention, isemployed in combination with a keyboard transmitter, the permutationbars 28 are each provided with a forked member 8| (Fig. 1). Articulatedto member 8| is a depending arm of a locking latch 82 pivoted on acommon shaft 83. In this manner, locking latches 82 are articulated tothe permutation bars 28 and are adapted to be rockedabout pivot shaft 63to either of two positions. Associated with latches 82 is acorresponding series of contact levers M for making and breakingindividual contacts 85. Contact levers 84 cooperate with individualcontact cams on cam drum 86 mounted on the transmitting shaft 81provided with a clutch mechanism 88 (Fig. 4) controlled by a trip member89, as set forth in U. S. Patent No. 1,965,602. U. S. Patent No.1,595,472 of August 10, 1925, discloses the cam drum assembly 86 andreference may be had to such patent for further details thereon. Tripmember 89'cooperates with a T-lever 9| pivoted to bracket 92. Thedepending arm of T-lever 9! is pointed as at 93 and is in the path of ashoulder 94 formed in a slidable member 95. The member 95 is secured toa universal bail 96 which is rotatably mounted on studs 9 (Fig. 1), andwhich is rotated upon the depression of any of the keys of the keyboard.The universal bail 96 and the member 95 are normally urged upwardly andrightwardly, respectively, by a spring 93. When the universal ball 96 isdepressed, the member 95 will be moved to the left against the action ofspring 98 and the shoulder M'Will engage the pointed end 93 of theT-shaped lever 91 and cause said lever M to be rotated clockwise (asviewed in Fig. 4) which action will cause trip member 89 to be rotatedout of engagement with portion 9i! of clutch 88 thus permitting theclutch 88 to operate through'one complete cycle in well-known manner.The universal bail 961s returned to its normal position by spring 98 sothat the member 85 will likewise be urged to its normal position.

In the operation of the transmitting unit, the depression of a key leverHi moves the bars l! and I8 permutably in accordance with apredetermined code combination, the setting of which,

through permutation bars 28, determines the positions of the lockinglatches 82. The rotation of cam-drum 36 is initiated substantiallysimultaneously with the setting of the locking latches 82, through theinstrumentality of trip member 89 which releases the clutch 88 forrota-' tion as previously described, and the locking loop 99,controlled'by a cam it! carried on a cam assembly freely mounted onshaft ti, is permitted to rotate in a counterclockwise direction (Fig.l)

to lock the latches 82 in their selected positions.

The setting of latches 82 determines whether the contact levers 84 shallor shall not be affected by their associated cams on cam drum 86 totransmit, through contacts 85,0ver a signal line to the receivingstation, a predetermined code combination of signaling impulses. Therespective notches in the cams on cam drum 86 are arranged in a-helicalprogression so that upon the rotation-of the cam assembly, the contacts85 controlled by levers M will be operated successystem.

With the apparatusaccording to the present invention,'itis' desired, insome instances, to

transmit directly to a line circuit, code combinations of impulsesrepresentative of the character keys operated, while in other instancesit may be more practical first to perforate a tape in accordance withthe key operated, and then to transmit subsequently the signalcorresponding thereto by means of a tape transmitter. To provide for theseveral possible conditions of operation, a switch is arranged in thekeyboardapparatus to control the transmission of impulses directly tothe line circuit, theperforationof a tape only, or the operation of thetransmitting distributor and the perforator simultaneously. The controlof these various conditions of operation is fully disclosed dependingarm iii. is integral to lever I09. function of stud I I2 is to controlfor adjustment purposes the angular relationship between levers acoaosein U. S. Patent No. 1,965,602. However, according to the presentinvention, the aforementioned switch has been modified to improve theoperation of the apparatus in effecting a transition from transmittingonly, or transmitting and per- 5 forating, to perforating. only.

As set forth in said patent, to control these various operations, aswitch lever or member N12. is provided which is pivoted at I53, andwhich assumes three positions; namely, an upper posi- 1 tion it'd (Figs.1 and 4), a middle position I05, and a' lower position we, and is heldin these representative positions through the cooperation of a bracketI81. As shown in Fig. 4, switch member N32 is provided with a bifurcatedend 1 which cooperates with a group of contacts, not here shown, butwhich is fully described in Patent No. 1,965,602. That-position of theswitch member 1&2 indicated N34 is referred to as the keyboard positionand is a position wherein direct keyboard transmission of signals to theline is effected; that is, each time a key lever is operated, thetransmitting cam drum to is rotated a single cycle to transmit a codecombination of signals through contacts 85 to the line. The position ofswitch member I82 indicated as I05 is known as the tape and'keyboardposition, and is that position wherein the perforator and transmittingmechanisms are conditioned to operate simultaneously. 3

The position of the switch member I62 indicated as tilt is known as thetape position, and in this position the transmitting cam drum is notinitiated into rotation; that is, the perforator may be operated withoutoperating the keyboard 3 transmitter. In moving the switch member N12 tothis particular position, the member 95 is moved through theinstrumentality of a fiat spring member let, which is secured to switchmember H372, to a position where its shoulder 94 is out of alignmentwith the pointed end 93 of the T-shaped lever 9|. Consequently, when theuniversal bail 95 is operated, the member 95 will not operate the clutchrelease lever 34, and hence the clutch 88 will not be released forrotation. Under these conditions, impulses will not be transmitted tothe line circuit, as previously described, upon the depression of thecharacter keys. The-spring #03 possesses the advantage of permitting themember 35 to be freed from point 93 of the T-shaped lever 91, which itnormally before the universal bail 96 draws member 95 forwardly. Thespring I68, therefore, performs the desired disengagement of the member95 from the lever 9| relatively early and yields during the latter partof the travel of the switch member I02.

Carried also on pivot Hi3 and adjacent to switch member I62 is a leverarm Hi9. Mounted on lever Hi9 at Hlis an eccentric stud H2. The The thatupon the depression of the switch member I52 to its lowest position,indicated H36 in Fig. 1, switch member 592 engages stud H2, and

through arm H3 causes the depression of uni- 7 versal' bail S5 in'whichdepressed position the universal b'ail 9E isretained so long as switchmember I62 remains-in said lowermost position.

Thus, upon'the depression of switch member I02 to its, lowermostposition, two operations occur 7 simultaneously; that is, the freeing ofshoulder 94 from point 93 by means of spring H13, and the depression andretention of universal bail 96. By means of this feature, the load oreffort of operating the universal bail 96 has been removed from keylevers It when the apparatus according to the present invention is beingused as a perforator only. However, each time a key lever M is operated,the universal bar previously alluded to for operating the punch magnetcontrol contacts 52 will be actuated, closing contacts 52 to complete acircuit to effect the operation of the perforator magnet 43.

While the present invention has been illustrated and described withreference to a particular structure, it will be understood that variousmodifications may be made without departing from the spirit of thepresent invention. Hence, all forms coming Within the scope ofequivalency of the appended claims are intended to be covered by theinvention.

What is claimed is:

1. In a telegraph keyboard unit, a rotary distributor, a stop engagingsaid distributor to prevent its rotation, a plurality of key levers, auniversal bail adapted to be controlled by said key levers, meansoperated by said bail for releasing said stop to enable said distributorto complete one cycle, means to hold said bail out of co operation withsaid key levers, and means controlled by said last mentioned meanseffective concurrently with the depression of said bail by said lastmentioned means to render said release means inefiective.

2. In a telegraph keyboard unit, a rotary distributor, a stop engagingsaid distributor to prevent its rotation, a plurality of key levers, auniversal bail adapted to be controlled by said key levers, meansoperated by said bail for releasing said stop to enable said distributorto complete one cycle, means to hold said bail out of cooperation withsaid key levers, and spring means controlled by said last mentionedmeans effective concurrently with the depression of said bail by saidlast mentioned means to render said release means ineffective.

3. In a telegraph keyboard unit, a rotary distributor, a stop meansengaging said distributor to prevent its rotation, trip means for saidstop means, a plurality of key levers, a universal bail adapted to becontrolled by said key levers, means operated by said bail for actuatingsaid trip means to release said stop means to enable said distributor tocomplete one cycle, means to hold said bail out of cooperation with saidkey levers, and means controlled by said last mentioned means effectiveconcurrently with the depression of said bail by said last mentionedmeans to render said trip means ineffective.

4. In a telegraph keyboard unit, a rotary distributor, a stop meansengaging said distributor to prevent its rotation, trip means for saidstop means, a plurality of key levers, a universal bail adapted to becontrolled by said key levers, means operated by said bail for actuatingsaid trip means to release said stop means to enable said distributortocomplete one cycle, means to hold said bail out of cooperation withsaid key levers, and spring means controlled by said last mentionedmeans effective concurrently with the depression of said ball by saidlast mentioned means to render said trip means ineffective.

5. In a telegraph keyboard unit, a rotary distributor, asingle-revolution clutch mechanism for controlling the rotation of saiddistributor, control means for said mechanism, a plurality of keylevers, a universal bail controlled by said key levers, means operatedby said bail for actuating said control means to release said mechanismto complete one cycle, means to hold said bail out of cooperation withsaid key levers, and means controlled by said last mentioned meanseffective concurrently with the depression of said bail by said lastmentioned means to render said control means ineffective.

6. In a telegraph keyboard unit, a rotary distributor, asingle-revolution clutch mechanism for controlling the rotation of saiddistributor, control means for said mechanism, a plurality of keylevers, a universal bail controlled by said key levers, means operatedby said bail for actuating said control means to release said mechanismto complete one cycle, means'to hold said bail out of cooperation withsaid key levers, and spring means controlled by said last mentionedmeans effective concurrently with the depression of said bail by saidlast mentioned means to render said control means ineffective.

7. In a telegraph keyboard unit, a rotary member, a stop engaging saidmember to prevent its rotation, a plurality of key levers, a bailcontrolled by said key levers, means operated by said bail for releasingsaid stop to enable said member to'complete one cycle, means to holdsaid bail out of cooperation with said key levers, and means controlledby said last mentioned efiective concurrently with the depression ofsaid ball by said. last mentioned means to render said release meansineflfective.

8. In a telegraph keyboard unit, a rotary memher, a single-revolutionclutch mechanism for controlling the rotation of said member, controlmeans for said mechanism, a plurality of key levers, a bail controlledby said key levers, means operated by said bail for actuating saidcontrol means to release said clutch mechanism to completeone cycle,means to hold said bail out of cooperation with said key levers, andmeans controlled by said last mentioned means efiective concurrentlywith the depression of said ball by said last mentioned means to rendersaid control means ineffective.

ROSS A. LAKE.

